In the discussion that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
In order to maximize the destructive energy into a target, two common approaches are employed. The first approach involves the delivery of kinetic energy to a target by utilizing relatively high velocity munitions, thereby capitalizing on the sensitivity of kinetic energy (Ek) to mass (m), and especially velocity (V), as manifested by the following equation:Ek=mV2/2
The second approach is to optimize the storage, and timely release, of potential energy (in the form of unreacted chemical energy) contained in a payload or fill material. This release of potential energy can be expressed by reference to the first law of thermodynamics, as represented in the following equation:dU=Q−W where dU is the change of internal energy of the warhead payload or fill material due to release of chemical energy, Q is the heat produced by the release of chemical energy, and W is the mechanical work done by the release of chemical energy.
It is widely accepted that the probability of target destruction is enhanced by increasing the energy delivered into the target. However, the choice between utilizing kinetic energy, chemical energy, or combination of both, to achieve the desired degree of lethality is mainly driven by the anticipated target set. For example, the kinetic energy of a bomb or missile would be equivalent to its mass at impact, multiplied by the square of its impact velocity, divided by two. The corresponding release of potential energy, thereof, for either of these munitions would be the enthalpy (heat) produced by the reacted warhead fill plus the mechanical work performed by the reacted warhead fill on any working fluid involved in the event. Both kinetic energy and released chemical energy is dissipated into a target and can be added numerically, with their sum representing the total delivered energy. In the case of bombs, the impact velocity is limited by kinematics and aerodynamic laws. The impact velocity of missiles is governed by the propulsion design and aerodynamic laws. In either case, the velocity is not easily increased to such an extent that the total deliverable lethality by the munition is substantially improved. Moreover, attempts to increase the velocity of the munition often involves trade-offs in other areas which may have detrimental impacts on the overall effectiveness and/or operation of the weapon system.
Certain energetic materials have been employed that are based on a mixture of reactive metal powders and an oxidizer suspended in an organic matrix. However, there are engineering challenges presented by such reactive materials. For example, a minimum requisite activation energy must be transferred to the reactive materials in order to trigger the release of chemical energy. There has been a general lack of confidence in the ignition of such materials upon impact at velocities less than about 4000 ft/s. In addition, since the above-mentioned materials are based on organic or polymeric matrix materials, which has a density less than that of most targets, i.e., steel, further acting to the detriment of penetration capabilities. Finally, components formed from such materials must possess a certain amount of structural integrity in order to afford proper functioning of the munition or munitions systems. For example, components formed from such materials must be able to if survive shocks encountered upon launch of the munition. Polymeric matrix material often lacks the above-mentioned reactive fragments may not possess the desired degree of structural integrity.
Thus, it would be advantageous to provide an improved reactive fragment which may address one or more of the above-mentioned concerns. Related publications include U.S. Pat. Nos. 3,961,576; 4,996,922; 5,700,974; 5,912,069; 5,936,184; 6,276,277; 6,627,013; and 6,679,960, the entire disclosure of each of these publications is incorporated herein by reference.